Common carriers, such as passenger airlines, bus lines, and train lines, frequently provide an assortment of personal electronic and entertainment options accessible and entertainment options accessible from the passenger seat. For example, to improve cabin service and make the flight more enjoyable, airlines may provide video and audio entertainment, including television, video games, internet access, and other in-flight entertainment (“IFE”) components. These amenities permit passengers to work, communicate, or be entertained during the flight without leaving the comfort of their seat.
Passenger IFE systems such as seat mounted flat screen video monitors and credit card activated cellular telephones are now most often mounted in the seat backs and arm rests of passenger aircraft. Some airlines also distribute personal DVD/CD players with a choice of movies/music. Passengers may even carry their own laptop computers or DVD/CD players and request power outlets. Within the confines of compact passenger seats fitted with conventional food service trays and arm rests, available space is often limited. In certain cases, the IFE equipment is fitted within the passenger seat itself. Thus, for IFE equipment such as a seat mounted display, the electrical wiring, components, processor unit, etc. is stored within an IFE box 18. The IFE box 18 is typically mounted on the side of the seat frame leg structure, thus inhibiting leg room, storage space under the passenger seat, and exposing the IFE components to debris and liquids.
Current seat design, specifically the seat pan, prohibits or limits airline technicians' access to the IFE boxes 18 when service is required and the technicians are forced to crawl on the floor of the aircraft (or possibly even remove one or more seats) in order to properly access and service the IFE boxes 18. This inconvenience greatly increases repair time and reduces accuracy, and often times requires a repair to be performed on an particular IFE box 18 multiple times until the issue is properly resolved.
U.S. Pat. No. 7,926,873 describes a pivotable seat pan 12, which provides access to the IFE box 18 from above a passenger seat 10. As illustrated in FIG. 1, the seat pan 12 is releasably coupled to a seat frame 14 via one or more coupling devices 20 comprising a ramp 22 mounted on a lower surface 36 of the seat pan 14 and a T-shaped projection 24 mounted on the seat frame 14. The ramp 22 comprises a track 26 that is partially enclosed along its length by a pair of lips 28. The ramp 22 has a length that corresponds to the distance traveled by the seat pan 12 when the passenger seat 10 rotates between reclined and upright positions. The projection 24 is inserted through at least one open end 34 of the ramp 22, wherein the pair of lips 28 slidingly lock the projection 24 to the ramp 22 during normal passenger use. As illustrated in FIG. 2, both ends 34 of the ramp 22 may be open, which allows the projection 24 to slide out of the ramp 22 when the seat pan 12 is positioned further forward or aft relative to the most forward or aft location of the seat pan 12 during normal passenger use. For example, in some instances, a technician may rotate the seat back 16 into a position that is more forward than the fully upright position available to a passenger during normal use, which causes the seat pan 12 to travel farther aft than the fully upright position. The projection 24 then slides out of the forward open end 34 of the ramp 22, thereby releasing the seat pan 12 so that it may be rotated upward to provide access to the area below.
While the coupling device described above provides a suitable solution for accessing the IFE box 18, there are certain instances where the coupling between the seat pan 12 and seat frame 14 may inadvertently disengage. For example, during a crash or Head Injury Criterion (“HIC”) testing (which is a measure of the likelihood of head injury resulting from an impact), a force may applied to the passenger seat back 16 that pushes the passenger seat back 16 more forward than the fully upright position, resulting in an inadvertent disengagement of the projection 24 from the ramp 22.
Various solutions have been attempted to avoid occurrences of inadvertent disengagement. For example, as shown in FIG. 3, an aperture 38 is formed in the ramp 22 in a location such that when a pin is inserted through the aperture 38, the T-shaped projection 24 is prevented from sliding through the forward open end 34 of the ramp 22. However, because the pin is inserted from above the seat pan 12, the pin is in contact with the seat cushion, which damages the seat cushion over time.
In other cases, as illustrated in FIG. 4, a sheet metal shroud 40 is positioned over the forward open end 34 of the ramp 22, which also prevents the projection 24 from sliding through the forward open end 34 of the ramp 22. However, the coupling design of the shroud 40 to the ramp 22 is cumbersome and time-consuming for the technician to engage or disengage the ramp 22 from the projection 24 to perform maintenance.
As a result, it is desirable to provide a latch that is configured to prevent inadvertent disengagement of the projection from the ramp, while also having a simple and quick locking design that requires no special tools to lock/unlock and that does not damage other seat components.